IYSC14 - Technical Outcomes and Competing Risk Analysis of In-Situ Fenestrated and Physician-Modified Endografts for the Endovascular Treatment of Thoracic and Complex Abdominal Aortic Pathologies

Objectives: This study aimed to describe the results of in-situ fenestration (ISF) and physician-modified endografts (PMEG) techniques and compare their outcomes, with a focus on target vessels (TV).

Methods: This single-center, retrospective, observational study included all consecutive patients treated with ISF or PMEG for thoracic or complex abdominal pathologies from January 2021 to December 2024. Primary endpoints were procedure-related and TV-related technical success, 30-day systemic complications, reinterventions and overall mortality. Secondary endpoints encompassed patient-centered estimated follow-up overall survival, freedom from aortic-related mortality and freedom from reinterventions, as well as TV-centered follow-up cumulative incidence of TV-related reinterventions and TV instability. To estimate TV-related follow-up outcomes, a competing risk analysis was performed.

Results: Forty-eight patients were included, with 28 (58.3%) undergoing ISF and 20 (41.7%) PMEG. Fifteen (31.2%) patients were treated in emergency/urgent setting (28.6% ISF vs 35% PMEG, p= .636). A total of 69 TVs were treated, comprising 26 (37.7%) left subclavian arteries and 43 (62.3%) visceral vessels. TVs were bridged using ISF in 34 (49.3%) cases and PMEG in 35 (50.7%). The median ischemia time required for ISF was 50, 35 and 20 minutes for left subclavian, renal and superior mesenteric arteries, respectively. The procedure-related technical success was 95.8% (96.4% ISF vs 95% PMEG, p= .807). The TV-related technical success was 98.5% (100% ISF vs 97.1% PMEG, p= .321). No significant differences in 30-day reintervention rates were observed (p = .936). Systemic complications were lower in the ISF group (22% vs 40%, p= .017). Three patients (6.3%) died within 30 days (2 in the ISF and 1 in the PMEG, 7.1% vs 5%, p= .762). At one year, the estimated survival rate was 68.2% for ISF and 75.4% for PMEG (p= .553), freedom from aorta-related mortality was 92% for ISF and 100% for PMEG (p= .212), freedom from reintervention was 79.5% for ISF and 82.6% for PMEG (p= .775) (Fig 1). Competing risk analysis showed a cumulative incidence of TV-related reinterventions at one year of 7.5% for ISF and 3% for PMEG (p = .6), and a cumulative incidence of TV instability of 7.5% for ISF and 6.1% for PMEG (p= .9) (Fig 2).

Conclusions: The initial results of using ISF and PMEG techniques are promising. ISF demonstrated lower systemic complication rates compared to PMEG, despite involving a significant period of TV ischemia. Furthermore, ISF achieved similar TV-related outcomes to PMEG despite the lack of fenestration surgical reinforcement.